Not by statute. Again, that depends. Each file has its own characteristics and may have different requirements in terms of timing. Some may be resolved very quickly at the triage level, where you say this allegation, even if true, does not come close to an offence, so that file is pretty easy to close. Other cases, again, will go to a full-fledged penal investigation.
On October 4th, 2011. See this statement in context.